ANINTRODUCTIONTOGIS

Summary

Introduction

Tutorials

The tutorials below illustrate several applications of GIS. These tutorials are based on the use of the free and open source software QGIS which can be downloaded here. Different data sources useful for making maps will also be presented.

I. Working with vectors

  1. Getting started with vectors processing
    This tutorial shows the basics of vector manipulation with QGIS (add vector layer, make a map based on a variable, add new variable to attribute table…)
    Data source: IGN BD TOPO

  2. Combine vector layers
    After having seen the basics of vector manipulation with QGIS, we will now see how the different layers can be combined.
    Data source: IGN BD TOPO

  3. Layout of a map
    In this tutorial we will see how to style a map with QGIS, and then export it as image or PDF.

  4. Join data table to vector layer
    This tutorial shows how to add a non-geographic data table (csv, xls…) to a vector layer.
    Data source: Dataset about the adoption of winter cover crops at the municipality level for mainland France

II. Working with rasters

  1. Georeferencing images
    This tutorial shows how to georeference historical aerial images, using already georeferenced recent data as a reference.
    Data source: IGN Remonter le Temps

  2. How to create a NDVI map
    This tutorial shows how to download the Sentinel-2 images provided free of charge by ESA and create a NDVI map from these data.
    Data source: ESA Sentinel-2

  3. Terrain analysis with Digital Elevation Model
    This tutorial shows how to use Digital Elevation Model (DEM) to produce various maps, such as relief maps.
    Data source: NASA Shuttle Radar Topography Mission (SRTM)

III. Combining rasters and vectors

  1. Convert raster to vector
    For a first example of an analysis combining rasters and vectors, we will see how we can convert a raster to a vector, so we can then perform the analysis using only the geoprocessing tools for vectors.

  2. Perform an analysis by combining raster and vector layers
    For this tutorial, we will study the distribution of crops by soil type. For this, we will combine a vector layer (the boundaries of the fields) with a raster layer (the soil map).
    Data source: SoilGrids and CAP field register

  3. Effect of past land use on crop development
    For this tutorial, we will see how we can create a vector summarizing past land use for a given field, and then evaluate the effect of land use evolution on crop wthin-field heterogeneity. More specifically, we will study the effect of previously forested areas.
    Data source: IGN Remonter le Temps (for past land use) and ESA Sentinel-2 (for current crop development)

Some additional map data sources

Global Human Settlement Layer Open and free data and tools for assessing the human presence on the planet
Open Street Map Access to Open Street Map data